In part of our contribution to reduce global warming, shall we ban the sports involvi

Well while you are at it, why not give up the comfort of zooming around using your own vehicle and always take public transport or carpool? Don't use air conditioners, don't travel by air unless it's a matter of life or death (certainly no vacations abroad). Always switch off lights when you leave a room and definitely reduce the time you spend on your computer. Reduction of global warming, like charity, starts at home. So do all the above and over time you will definitely make as much of an impact as you were hoping to make by banning sports using fossil fuels. And if you decide you can't do all this then lets not presume to preach what we can't practice.